ZINC-CARBON BATTERIES 8.25
FIGURE 8.17 Comparison of Leclanche´ and zinc-chloride D-size batteries of various grades,
continuously discharged through 2.2 ohm at 20⬚C. GP-general purpose; HD-heavy duty; EHD-
extra heavy duty.
The relative performance of both Leclanche´ and zinc-chloride AAA, AA, C, and D-size
batteries roughly follow a 1:2:8:16 proportion to the 0.9-V cutoff for the low rate and a 1:
2:12:24 proportion for the high-rate drain, illustrating the advantage of the lower current
density discharge for the larger batteries. The high discharge rate for the general-purpose C-
and D- size batteries at 300 mA (3.9
⍀) is shown in Fig. 8.16 compared with the performance
of the general purpose larger No. 6 battery for which this discharge rate is low.
8.6.5 Comparative Discharge Curves—Different Battery Grades
Figure 8.17 compares both Leclanche´ and zinc-chloride general purpose (GP), heavy duty
(HD), and the extra/ super heavy duty (EHD) D-size batteries (as defined in Sec. 8.3) dis-
charged continuously through a 2.2-
⍀ load at 20⬚C. A performance ratio, to the 0.9 V cutoff,
of 1.0:1.3 between the Leclanche´ and zinc-chloride GP batteries was observed. The same
ratio for the HD batteries was 1.0:1.5 respectively. Comparison between the Leclanche´ (LC)
and zinc-chloride (ZC) GP, HD, and EHD batteries showed ratios of 1:1.3:2.2:3.4:4.4 for
LC,GP:ZC,GP:LC,HD:ZC,HD:ZC,EHD respectively.
Figure 8.18 shows a comparison of the same battery grades discharged intermittently
through a 2.2-
⍀ load on the American National Standards Institute (ANSI) light intermittent
flashlight (LIF) test. On this regimen, the performance ratio to the 0.9 V cutoff is 1:1 for
the GP batteries, 1:1.3 for the HD, and for the LC,GP:ZC,GP:LC,HD:ZC,HD:ZC,EHD,
1:1:1.7:2.1:2.9, respectively. Testing on the intermittent discharge, which allows for a rest
period for recovery, results in increased performance for all batteries and evidences a de-
creased difference in performance between the grades.
Figure 8.19 illustrates the same battery grades discharged continuously through the lighter
3.9-
⍀ load. The following ratios were obtained; 1:1.3 GP, 1:1.4 HD, and 1:1.3:2.0:2.8:3.5
between all grades to the 0.9 V cutoff. Less of a difference was observed than that obtained
at the heavier 2.2
⍀ discharge rate. The slower reaction rate at the lighter drain is evident
because of the higher battery voltages. A comparison of an intermittent discharge at 3.9
⍀